Career
Tomkinson joined the Royal Navy in 1891 and served in the destroyer HMS Fame during the Boxer Rebellion in 1900. He served in World War I initially commanding the destroyer HMS Lurcher and seeing action at the Battle of Heligoland Bight in 1914 and the Battle of Dogger Bank in 1915. His war service continued as Senior Naval Officer, British submarines in Venice in 1915 and as Commander of the light cruiser HMS Aurora in 1916 before seeing action again during the Zeebrugge Raid and the Ostend Raid in 1918.
He then became Commanding Officer of the Battlecruiser Squadron in 1931 before being placed in temporary command of the Atlantic Fleet later that year: it was under his command that the Invergordon Mutiny took place and, following the conclusion of the mutiny, he was blamed for being too lenient with the mutineers and placed on half pay.
He retired in 1935 but was re-employed during World World War II as Flag Officer in charge of the Bristol Channel before retiring again in 1942.